Continuing support is requested for five predoctoral graduate students per annum to participate in a Training Program in Developmental Biology. Graduate students in this Program become expert in the concepts of modern cell, molecular and developmental biology and the application of molecular, cellular, morphological, and organismic methodologies to the mechanisms underlying embryonic development, reproduction, tissue remodeling, and disease processes involving alterations in cell behavior. Several major themes of research are available to the students: 1. early vertebrate development and reproductive biology; 2. tissue and organ development and remodeling; 3. disease processes, such as cancer, aging and vascular disease, resulting from disturbances in cell behavior and tissue remodeling; 4. basic molecular and cellular mechanisms relevant to development. The unique strengths of the Program derive from the established strength of the faculty, the sustained retention of a strong pool of matriculants into the Program over the past decade or more, the intense concentration and collaboration on mechanisms of dynamic cell behavior in the above systems, the broad range of technical expertise of the faculty, the availability of top-grade facilities that allow sophisticated technology to be used, the location of the Program in a very strong Health Science research environment that facilitates collaborations, the interactive nature of the Program members, and the close attention given to trainees in the small to moderate-size laboratories of the Program. On graduation, trainees will receive a Ph.D. in Cell, Molecular and Developmental Biology from the Tufts University Sackler School of Graduate Biomedical Science.